The influence of temperature on reproductive success and oxidative metabolism in Desert Pupfish.

Authors: Jones, Alexander*, Lim, David, Hillyard, Stanley, Breukelen, Frank

Year: 2015 (xlvii)

Abstract

The Devils Hole Pupfish, Cyprinodon diabolis, is restricted to only Devils Hole in Death Valley National Park. The main pool of Devils Hole almost never sees temperatures below 33 Á‚°C and is notoriously energy and oxygen limited, though temperatures fluctuate seasonally on the breeding shelf. We aimed to better understand the oxidative metabolism requirements of lab reared pupfish in eggs, larvae, and adults in Point of Rocks Á¢â‚¬Å“refugeÁ¢â‚¬Â fish derived from C. diabolis and in its close relative C. nevadensis mionectes. Fish reared at 33 Á‚°C often undergo long periods with little or no oxygen consumption, during which time body function does not appear to be depressed and ventilation rate is maintained. Á¢â‚¬Å“RefugeÁ¢â‚¬Â eggs closest to hatching consumed ~43% less oxygen at 33 Á‚°C than at 28 Á‚°C, though time to hatch decreased at the higher temperature. Á¢â‚¬Å“RefugeÁ¢â‚¬Â eggs did not show a significant increase in oxidative metabolism at any point during egg development at the higher temperature despite decreased time to hatch. These data suggest that anaerobic pathways may be important for pupfish that live in high temperature regimes in all life stages. Survival of eggs from parents acclimated to 33 Á‚°C was very low, indicating that these fish may not be well adapted to water temperatures typical of their natural habitat. Some pupfish species may not be as tolerant of high temperatures as previously assumed, which may have profound implications for the conservation of this group as global temperatures rise.